Der Valentinstag (am 14. Februar des Jahres) gilt in einigen Ländern als Tag der Liebenden. An Popularität gewann er durch den Handel mit Blumen, besonders jedoch durch die umfangreiche Werbung der Floristen. In Europa handelt es sich um einen primär kommerziellen Anlass, der mit traditionellem Brauchtum verbrämt wird, ähnlich dem in den neunziger Jahren populär gewordenen und über die USA aus Irland importierten Halloween. Der Name des Tages wird heute zumeist auf die Sage des Bischofs Valentin von Terni zurückgeführt.

The Valentine’s Day is on February 14. It is the traditional day on which lovers express their love for each other; sending Valentine’s cards, candy, or donations to charities, often anonymously. It is very common to present flowers on Valentine’s Day. The holiday is named after two men, both Christian martyrs named Valentine. The day became associated with romantic love in the High Middle Ages, when the tradition of courtly love flourished.

The first recorded association of Valentine’s Day with romantic love is in Parlement of Foules (1382) by Geoffrey Chaucer[1]:

For this was on seynt Volantynys day
Whan euery bryd comyth there to chese [chose] his make [mate].

February fertility festivals

On the ancient Athens calendar, the period between mid-January and mid-February was the month of Gamelion, dedicated to the sacred marriage of Zeus and Hera.

In Ancient Rome, February 15 was Lupercalia. Plutarch wrote: Lupercalia, of which many write that it was anciently celebrated by shepherds, and has also some connection with the Arcadian Lycaea. At this time many of the noble youths and of the magistrates run up and down through the city naked, for sport and laughter striking those they meet with shaggy thongs. And many women of rank also purposely get in their way, and like children at school present their hands to be struck, believing that the pregnant will thus be helped in delivery, and the barren to pregnancy.
The word Lupercalia comes from lupus, or wolf, so the holiday may be connected with the legendary wolf that suckled Romulus and Remus. Lupercalia was a festival local to the city of Rome.
The more general Festival of Juno Februa, meaning “Juno the purifier” or “the chaste Juno,” was celebrated on February 13-14.

Pope Gelasius I (492-496) abolished Lupercalia. Some historians argue that Candlemas (then held on February 14, later moved to February 2) was promoted as its replacement, but this feast was already being celebrated in Jerusalem by AD 381. The pope also declared in 496 that the feast of St. Valentine would be on February 14.

http://de.wikipedia.org/wiki/Valentinstag
http://en.wikipedia.org/wiki/St._Valentine%27s_Day